Bearing a cab with streamlined nose at each end, the B Class were the first mainline diesels to enter service with Victorian Railways. They were the first class of diesel locomotives in Australia to have a Co-Co wheel arrangement, which soon became standard on mainline diesel locomotives. Eleven of the class were rebuilt as the A Class during the 1980s. B76 and B80 are on hire to Qube. B61 was painted in ‘Streamliners’ livery in 2016.